Techno-economic feasibility analysis of hydrogen production by PtG concept and feeding it into a combined cycle power plant leading to sector coupling in future

Power-to-Gas offers an efficient opportunity to turn renewable energy into "green" hydrogen, establishing an inevitably remunerative spectrum of end-uses. In this spirit, the current paper intends to establish a techno-economic perspective by evaluating a hybrid energy system model for sizing hydrogen generation by water electrolysis from renewable energy and using it in thermal power plants for electricity production for localized grids in Pakistan. Modeling of this hybrid system is done using HOMER Pro. Hydrogen is produced using a hybrid energy system and then fed into a hypothetical combined cycle power plant to produce electricity. Hydrogen has economic dominance over batteries in terms of energy storage and cost of energy, as per results. Four scenarios regarding proposed system configurations are considered in this study pondering upon how hydrogen can be produced from the perspective of cleaner production and assessing it techno-economically. Firstly, base case scenario consisting of wind turbine generators, genset, solar panels, batteries, convertor, electrolyzer and hydrogen tank is evaluated. Scenario -1 is analyzed on the basis of techno-economic evaluations, excluding Li-Ion batteries from the base case. For scenario - 2, Li-Ion batteries have been included and genset is excluded from the system architecture to provide backup power to the electrolyzer during hours of intermittency aiming at least interruption. Lastly, scenario - 3 is exclusive of the photovoltaics and all rest remain intact. The economic analysis is constructed on economic parameters like payback period, internal rate of return, and cost of energy, and multiple configurations of the system. The most feasible configuration yielded levelized cost of energy being 0.465 USD/kWh, internal rate of return being 17.3 %, and payback period of 2.3 years. Renewable energy sources are thoroughly assessed for coupling with the desalination plant and electrolyzer array. This system can further be expanded on a larger scale to transform the region into a hydrogen hub to produce green, high-energy-density hydrogen to be supplied to and utilized by multiple sectors.